Positive top-line Ph III RLS data on XenoPort's XP13512

USA-based XenoPort has reported positive top-line results from a Phase III trial of its drug candidate XP13512 for the treatment of symptoms of primary restless legs syndrome (RLS). The agent demonstrated statistically-significant improvements compared to placebo on both of the co-primary endpoints of the trial and was also well tolerated.

The double-blind, placebo-controlled study enrolled 222 RLS patients who were treated with either 1,200mg of XP13512 or placebo, given once per day. Treatment with the agent was associated with a statistically-significant placebo-adjusted improvement in the co-primary endpoints - change from baseline for the International RLS rating scale score at end of treatment and the percentage of patients showing significant improvement on the Clinical Global Impression of Improvement scale.

Improvements in the IRLS Scale were significantly greater for XP13512 than for placebo (-13.2 vs -8.8; p=0.0002). At the end of treatment, significantly more patients treated with XP13512 were reported as "much improved" or "very much improved" on the CGI-I scale compared to those given placebo (76% vs 39%; p<0.0001).